Including 3rd party modules in a Blender addon
DingTo created the Windows builds of numpy. You can find some info in this task's discussion, especially Juicyfruit's wiki page should be of interest.

The compiled numpy libs were added to the library repository and are placed in the site-packages folder when you build blender.

You will have to


provide a complete, customized blender buildor
ask your users to manually place the required lib in blender's site-packages folderor
add the lib to your addon's folder and import it from there (sys.path.append should do the trick)